Skill mix changes: substitution or service development?

An extensive review of published studies where doctors were replaced by other health professions demonstrates considerable scope for alterations in skill mix. However, the studies reported are often dated and have design deficiencies. In health services world-wide there is a policy focus which emphasises the substitution of nurses in particular for doctors. However, this substitution may not be real and increased roles for non-physician personnel may result in service development/enhancement rather than labour substitution. Further study of skill mix changes and whether non-physician personnel are being used as substitutes or complements for doctors is required urgently.